How to add mp3 or videoclip into your blogspot account

Recently i had try to renew my nuffnang advertisement in my blog. After i log in to my nuffnang account the i only know that i can post a coding things without editing my HTML code. What are new thing, maybe i had left my blog around half years and became outdated..lol
how to add some html coding application into your blog?
firstly,you need to copy the code such as video or song...Then you need to do as follow:
Forgotten the link: http://www.mp3glam.com/
1. Copy the video or mp3 song code from website
2.Click design in your account
3.Add gadget
4.Select HTML/java script
5.Then paste your code inside the boxes
6.Last click SAVE...
Its DONE...
Go view your lastest blog?...any changes?can hear song or watch videoclip already right?:P